An absorbent article refers to products such as diapers, sanitary napkins, training pants, incontinent garments, overnight pads, panty liners, underarm shields, and the like which are used to absorb body fluid, such as urine, menses, blood, perspiration, and other excrements discharged by a body. Sanitary napkins, also referred to as catamenial pads, feminine pads, overnight pads, panty liners and panty shields are designed to be worn by a female to absorb menses and other body fluids discharged before, during and after a menstrual period. Such products are external devices which are generally held in position by a garment attachment adhesive or by a mechanical attachment to an adjacent undergarment. Such products differ from tampons which are classified as internal devices and which are designed to be physically inserted into a woman's vagina.
Functionally, sanitary napkins and overnight pads differ from panty liners and panty shields in that they are generally constructed to absorb a greater quantity of body fluid and are designed to be worn for a longer period of time.
In order to adequately perform their function, modern catamenial products are constructed of highly absorbent materials. However, if any absorbent material is utilized up to the point where it becomes fully saturated, there is a possibility that leakage of body fluid could occur. Such leakage could stain the user's clothing. Many times, leakage occurs before the absorbent is near its maximum absorbent capacity because only a small portion of the absorbent is utilized. It is therefore, desirable to construct, an absorbent article which has the capacity to rapidly wick the fluid to a large portion of the absorbent so as to prevent premature side leakage.
It is also desirable to construct an absorbent article which can supply an in-use visual signal to the user that the body fluid which entered the article will stay in the center thereof. A post-use visual signal is also beneficial in letting the user know that the fluid has remained in the center of the absorbent article thereby reinforcing the in-use visual signal. The post-use visual signal also lets the user know that the article may be approaching it's saturation limit and that it may be time to change the article.
Therefore, there is a need to provide an absorbent article which can rapidly wick fluid throughout the absorbent and which can provide the user with a post-use visual signal to determine if it is near its absorption limits. If the absorbent article is close to its limit, the user could then replace the product before leakage occurs.
Another important aspect of a catamenial product is its ability to wick menses. Menses is very viscous and can contain small particles of body tissue which tend to cling to the cover and can restrict the passage of additional body fluid into the absorbent article. Manufacturers of sanitary napkins are always on the lookout for a new material or a synergistic effect of rearranging known materials to obtain a structure which has improved wicking capacities.
Now an absorbent article has been invented which has rapid wicking capacity within the absorbent, as well as providing both an in-use visual signal showing that the fluid will stay in the center of the article and a post-use visual signal indicating when the article is approaching it's saturation limit.